The present invention relates in general to a thrust-torque detector, and more particularly to an element or device which is fitted to a rotating shaft of a rotational machine such as machine tools, though not limited thereto, to detect the thrust and/or torque applied to the rotating shaft.
One application for such a thrust-torque detector is a cutting dynamometer measuring cutting resistance, and various designs of cutting dynamometers have so far been made. However, there is still room for improvement in these designs to make the cutting dynamometer applicable to such a machine as a large-sized drilling machine and to meet the basic requirements that it has a large gain, that the mutual interference is minimal when a force is divided into two components to be measured, that the measurement has linearity without hysteresis, that there is little effect on the output even when the point of application is changed, and that the frequency characteristics are fixed within a required range, etc. Such a detector is indispensable to give a self-diagnosis function to machine tools required, for instance, to have a high level of automation thereof.